The query used to get the status of an assign submission for the course overview block (assign_print_overview) will not always return the correct result when multiple submissions exist for a user. The query and use of its result is done in such a way that it only supports a single submission.

https://github.com/moodle/moodle/blob/master/mod/assign/lib.php#L443

Notice: Did you remember to make the first column something unique in your call to get_records? Duplicate value '1' found in column 'assignment'.

* line 980 of /lib/dml/pgsql_native_moodle_database.php: call to debugging()

* line 479 of /mod/assign/lib.php: call to pgsql_native_moodle_database->get_records_sql()

* line 43 of /blocks/course_overview/locallib.php: call to assign_print_overview()

Query will need a more unique key (a.id + s.id maybe?) and php code to then report on the most recent submission for that user.